Refactor AJAX function to 1) not graft data onto error object & 2) not manage links data itself

[goller]

This code https://github.com/influxdata/chronograf/blob/master/ui/src/utils/ajax.js#L53 ended up causing issues downstream (see #1476)

@cryptoquick had an idea that we could use symbols (http://exploringjs.com/es6/ch_symbols.html) for additional properties of response objects rather than mashups.

[jaredscheib]

1. The AJAX function in ajax.js is managing links state in a way that has led to much confusion, and seems outside of the scope of what it should be concerned with.
2. Additionally, we're grafting data onto the error object, which leads to downstream confusion and challenges.

It would be good to clean up both of these so that we can straighten out how we handle links and errors throughout Chronograf.

• [ ] refactor AJAX function by removing links request from it and instead sending a separate links request (via action creator) and store the response in Redux
• [ ] refactor to pass these known links to the AJAX function at all times
• [ ] refactor AJAX function to simply pass through received error, & fix errorsMiddleware or anywhere else that's attempting to use this grafted errors object

It looks to me currently like this complexity was introduced in order to make it so that an ostensibly older pattern of passing in resource to AJAX could be accommodated. So one simple solution to clean all of this up is to simply refactor any cases of resource to an actual link that the server ought to provide, adding links to those provided by the server as needed.

[russorat]

closing due to inactivity